Showcase refrigerator



June 27, 1933. v. P. WARREN 1,915,704

' SHOWCASE REFRIGERATR Filed Jan. 28, 1931 2 Sheets-Sheet l .E'll

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SHOWCASE REFRIGERATOR Filed Jan. 28 1931 2 Sheets-Sheet 2 Patented lune2?, i833 'iftrlb E?. WARREN, 0:5 ATLANTA, GEORGIA SHWGASE REFRKGEPATQRyThis invention relates to showcase refriger ators and particularly toshowcases of that type in which the window, for heat insulatingpurposes'7 is constructed with alternate lami- 5 nations of glass andair.

ln my Patent No. 1,856,008, granted April y 26, 1932, is described asystem -lfor maintaining visibility through the showcase window byinhibiting moisture condensation on au the panes, or removing suchmoisture as may have condensed thereupon, by establishing a dehydratingcirculation for the air withincondense on the respective inner panes atthe temperatures of said panes, and means for elevating the temperatureof the outer pane above the condensation point of the uncontrolledhumidity of the atmosphere.

Another object of the invention is the construction of the heating meansand the relation of its elements to specific regions of the area of theouter surface ofthe outer glass.

Other objects of the invention will appear as the following descriptionof a preferred and practical embodiment thereof proceeds. In thedrawings in which the same characters of reference have been usedthroughout the several ligures to designate identical parts: q.

Figure 1 isa perspective View of a refrigerated showcase embodying theprinciples of the invention;

Figure 2 is a similar viewparts being removed and parts being shown insection to illustrate the details of construction;

Figure 3 is a cross section through the window portion of the showcase,parts being omitted;

Figure 4 is an exploded perspective View of the reflector;

`els by pipes 5 and 6 communicating with the Figures 5 and 6 arerespectively, rear and front views ola corner of the outer glass panelshowing details of the rheostat construction, Figure 6 showing alsodiagrammatically the preferred relation of the rheostat circuit to thelighting circuit;

Figure 7 is a cross section taken along the line 7-7 of Figure 6; and

Figure 8 is an end view of the corners of Y the panel shown in Figure 6.im

Referring to the several ligures, the numeral l represents arefrigerated showcase having the front display window 2. A refrigeratingcoil, not shown, may be suitably positioned within the chamber of theshowcase, and with a view to conserving the low temperature of theshowcase the Window is constructed of a plurality of layers or panels 3of glass separated by insulating air spaces 4. Figure 3 shows that thespaces between the glass panels are suitably sealed so as to constitutesaid spaces as air cells, the nature of the sealing means not being suchhowever, as to preclude enough leakage to provide for breathing in andout by the air in said cells to compensate for expansion and contractionof said air due-to temperature changes both inside and outside of therefrigerator showcase. lf the vpressure within and without the air cellscould not be equalized by such respiration, the glass panels would bcrushed in by atmospheric pressure at periods of depression withinsaidair cells.

Through the respiratory interchange of air above referred to, a certaindegree of humidity occursin saidv aircells which may condense into amist upon the glass panels impairing visibility of the displayedcontents of the showcase. v

For the purpose of reducing the humidity of the enclosed air below thepoint at which the moisture will condense upon the glass panels, acirculationsystem isprovided including a drier 4 containing chloride ofcalcium or other drying agent and being connected to the air cellsbetween the glass pansaid air cells preferably at their opposite 1 ends.A fan 7 creates thecirculation and l region of the glass.

Awall of the showcase.

a valve 8 provides means for selectively determining the circulationthrough any of the individual air cells to the exclusion of the others.`All this is described in detail in my hereinbefore mentioned companionapplication and it is also fully explained in said application how themoisture may collect first on the innermost glass due to its temperaturebeing the lowest and the advantages of providing for the individualdehydration of the several air cells.

Since the front or outermost glass panel 9 is subject to thecondensation thereupon of the humid air of the store atmosphere, whichhumidity cannot be controlled, means is provided Jfor heating the frontglass panel. These means provide a lamp and reflector 10 at the top ofthe panel and a rheostat 11 adjacent its lower edge. y'llhe lamp andreflector may be relied upon to heat the upper half of the glass to atemperature at which atmospheric moisture will not condense upon thesurface of the glass while the rheostat is employed -for heating thelower por tion of the glass. ln practice, moisture will be found tocollect on the. lower portion of the window first, since the lower partof the refrigerated chamber is somewhat colder than the upper part.

The reflector comprises a silvered or polished trough-shaped member 12,the surface of which is prismatic rather than cylindrical in alongitudinal direction, providing rectangular reflector facets 13forrefleeting the heat from the electric lamp 14 against the upperportion of the front glass. By having the reflecting surface facetedinstead of curved the reflected heat is thrown in successive bands uponthe glass rather than being reected in a mere line formation,

thus distributing the heat with more or less uniformity over quite anarea in the upper Y rlhe reflector may be screwed or otherwise suitablysecured to a molding 15 which holds the glass panel in place at the topbut this means of securing the reflector is merely suggestive and not atall limitative in its bearing upon the invention. It is highly desirablehowever that the v reflector 13 make metallic contact with the a heatconducting element for imparting heat V directly to the glass panel byconduction.

The reflector is preferably provided with a removable hood 17 having achannel 18 at the bottom which overlapsvthe lower free end of thereflector and having a flange 19 at the top adapted to be secured to thefront 'A conduit 2O is formed between the reflector 13 and the hood 17which may receive the wires which fit the electric lamps 14. u j

The lamps may be spaced at any desired interval between the reflector'and the glass panel.

Referring to the rheostat 21, it will be 0bserved that the lower part ofthe glass panel is provided with longitudinal grooves 22 extending thelength thereof and across the ends of said panel so as to provideprojections 23 -at said ends. An appropriate length of high resistancewire 24 is laid in said grooves passing around the projections 23 andbeing retained in place by said projections. The ends of. said highresistance' wire are suitably secured to the glass panel by means suchas the binding screws 25 and 26, said screws being preferably concealedbeneath the bead which covers the adjacent edge of the panel 9.

Figure 6 shows that the rheostat is preferably connected in series withthe lighting circuit of the showcase vso that when the lighting switch27 is closed, both the lamps and rheostat operate together.

rlhe grooves 22 are quite deep and the wire 24 is disposed at the bottomof said grooves so that the glass absorbs most of the heat radiated bysaid wire. on the outer side of said wire with a cementitious substance28, water-proof and of electrical insulating nature, and permanentlyflexible so that it will not crack from the expansion of the wire 23when the latter is heated. By virtue of the fact that lthe wire isbacked by the' flexible cementitious substance its expansion will notstress the glass. Since as has been previously stated, the tend ency ofthe condensed moisture is to collect first at the lower part of theglass, especial provision is made Jfor moisture-proofing the rheostat.With this object in view a strip of mica 29, shown in Figures 2 and 3 isplaced The grooves are filled upon the layer of cementitious substanceand This forms a molding 30 of hard rubber or other suitable moistureproof and dielectric substance is placed against the mica, covering andconcealing the entire rheostat, and a layer of water-proof cementpreferably intervenes the adjacent faces of the molding 30 andthe micastrip.

In the practical application of this invention to the window of arefrigerated showcase, the side and top members of'the molding or framewhich retains the front panel may for purposes of economy be made ofwood and areprefera'bly of the same color 'and shape as the molding 30so as to give the appearance of similarity to all four sides of themolding or frame.

ln the operation of my invention, the presence of moisture upon anyoneor more of the interior panels of glass indicates the need fordehydrating the air in the cell or cells switch is closed,simultaneously actuating iarnps and reflector.7 and the rheostat.

is obvious that changes in the ment ot the several parts or aiterftionsin the. details ot construction there@ may be rende it desired Withouttranscending the spirit and scope of the invention as claimed.

-What claim is:

l. In a refrigerated showcase. a window comprising a plurality of spacedglass panels defining a plurality of air cells therebetween, means forselectively reducing the humidity of the air in said air cells below thepoint at which moisture will condense from said air on to the glasssurfaces bounding said air cells, in combination with means for raisingthe temperature of the outside glass panel to such a pointthat moisturewill not condense upon the outside surface ot said panel from theatmosphere outside of the showcase.

In a refrigerated show/case as claimed in claim 1, the means for raisingthe temperature ot the outside panel comprising an illuminative heatsource adjacent the top et said outside panel, and a rheostat adjacentthe bottom of said panel in series circuiti with said illnminatire heatsource.

3. ln a refrigerated showcasen a Window comprising a plurality of spacedglass panels defining a plurality of insulating air cells therebetween,and means for raising the temperature of the outside panel including anilluminative heat source adjacent the top of said panel, and a concavereflector having a longitiulinally faceted surface associated with saidilluminative heat source tor reflecting heat upon the'upper portion otsaid panel in a Zone oi considerable width.

Zi. in a refrigerated showcase, a Window comprising a pilnralitj,Y ofspaced glass panels defining a'piurality of air cells between panels,means tor raising the tempera-- vture o1? the outside glass panel suchpoint moisture Wilt not condense upon. the outside ot said panel fromthe atmosener outside the showcase said ineens coni- A "l l l l) n u prinigh. resistance electric heating dosed adjacent hott-om or 1 Cilgrooves formed adjacent the lower edge otflexible dielectric andmoistureproof eem' entitious substance permitting expansion ot" saidhigh resistance Wire Without stressing the glass ot said panel.

6. ln a refrigerated showcase, a glass panel forming the outside memberof a laminated insulating Window, means for heating said glass panel toprevent condensation thereupon of atmospheric moisture, said meanscomprising a high resistance wire Wound in grooves formed adjacent thelower edge of said panel and in substantial contact with the glass atthe bottoms of said grooves, a flexible, dielectric, moisture-proofcemen titious substance filling said grooves, a thin sheet of insulatingmaterial covering said grooves and being adhered by said cementitioussubstance, and a molding of electrical insulation material secured incontact with said sheet and concealing said heating means.

'7. lWindow panel for refrigerated showcase comprising a glass sheethaving grooves formed longitudinally of an edge thereof, a highresistance Wire arranged in said grooves in contactive relation to theglass at the bottoms of said grooves, parallel portions ot said Wirebeing separated by the 4rilos defined between adjacent grooves, thegroove portion ot said glass being tilled in above said high resistanceWire, and athin sheet of insulating material over-lying said grooves andcemented thereto by said cementitious substance, the terminals of saidhigh resistance wire being fined to suitable connectors carried by saidglass sheet.

'in testimony whereof ll ama my signature.

HRG-EIL l?. W

